In the field of consumer electronics, for example smart phones, tablet computers, and other portable electronic devices, there is a need to use three-axis compass combined with inertial measurement devices such as a three-axis gyroscopes, and three-axis accelerometers, in order to form a complete 9-axis inertial magnetic navigation unit. These three-axis compasses can simultaneously measure three magnetic field components at the same time, and they are composed of AMR, GMR, or TMR magnetoresistive sensors. These magnetoresistive sensors detect the magnetic field in the plane of the substrate, such that two magnetic field components, X, Y, can be detected by tow orthogonal magnetoresistive sensors on the same substrate, in order to realize a two-axis XY magnetic field sensor. However, for the Z-axis magnetic field component, one solution is to use a one-axis sensor installed on an orthogonal plane. This method has the following shortcomings:
1) An XY magnetic sensor with a Z-single axis magnetic sensor cannot be accomplished in a fully integrated manufacturing process, thereby adding complexity.
2) Relative to a fully integrated manufacturing process, the assembly of individual sensors into a three-axis compass is not very accurate, which impacts the accuracy of the resulting sensor.
3) Because the one-axis Z-axis magnetic sensor has a sensing axis perpendicular to the XY two-axis magnetic sensor, the size of the resulting three-axis magnetic field sensor is larger; this increases device size and increases complexity of the packaging process.